Re: Beginner Questions about Core and Bobbin

> We are two high school physics students trying to build the Tesla Coil at
> http://www.e-etc-dot-com/electronics/hivolt/tesla/tesla.htm.  We have already
> purchased all of the parts for the coil on this page and have everything
> completed except the core.
> We cannot find anybody who can supply the AMIDON EA-77-250 ferrite core
> bobbin.  We are hoping that a cast iron pipe and iron rod will substitute
> for the core and bobbin.  Is this correct?

I doubt it, the iron is conductive which is like a shorted winding and the
net result will be a warm core and almost no power

>If not then what should we use.

all that seems to be described is a transformer with a 1:10 ratio, i'm sure
if you look through a catalogue you can find a similar transformer, an audio
impedance matching transformer might be a good place to start, if not and
you want to wind your own im sure the part no isn't critical, most
electronics shops/sites will have tranformer bobbins, they are specially
shaped ferrites for winding small transformers about 4" * 2" * 2" (usually)
which are in two parts for easier winding

> What should be the dimensions of the core and bobbin.  We have tried
> contacting the person who posted the page, but he did not write the page.
> He found it elsewhere on the net and is not able to help us.
> We don't really know for sure what the core and bobbin is.  We are
> that they are similar to a pipe and rod with the core (or rod) fitting
> inside the bobbin (pipe) is this correct?

if you want to see what a ferrite and bobbin looks like go to
http://rswww-dot-com/ and look under electronic>ferrites>tranformer core or
something of the like

i am no the world expert on this so if anyone knows better please tell me